A&P Exam 3

Question 1

How is the spinal cord protected?

Answer 1

Isolated from body via vertebrae column, tendons, muscles

Spinal meninges – specialized membranes that provide phys support and stability

Question 2

Structures covering spinal cord

Answer 2

vertebrae
epidural space with fat
dura matter (“tough mother” in latin)
Subdural space (filled with interstitial fluid
arachnoid matter (“spider mother” – it’s like a web of collagen fibers) & subarachnoid space (CSF in between the webs)
Pia matter (“gentle mother”)

Question 3

Meninges of spinal cord

Answer 3

Dura matter
tough collagenous membrane surrounded by epidural space, contains fat and blood vessels
Arachnoid matter
layers of simple squamous epithelium lining dura and loose mesh f fibers with csf
Pia Matter
delicate membrane that adheres to spinal cord
filium terminale and denticulate ligaments anchors the cord

Question 4

Spina bifida

Answer 4

congenital defect in baby (1 out of 1000)
the failure of vertebral arch to close covering spinal cord
mothers can reduce risk of folic acid supplement during pregnancy (we don’t know why it works yet, but knows it does)

Question 5

Inferior end of spinal cord

Answer 5

conus medullaris
filum terminale
thread-like extension of pia matter
cadua equina (these nerves come off in the shape of a horse's tail)
spinal segment

Question 6

Dorsal root ganglion

Answer 6

cell bodies of sensory nerves

Question 7

Ventral or anterior root ganglion

Answer 7

outgoing motor fibers

Question 8

Gray matter of spinal cord

Answer 8

shaped like letter of H or butterfly
(grey matter means soma of neurons – they have no lipids and aren’t myelinated)
Paired dorsal and ventral gray hors
lateral horns only present in thoracic spinal cord
gray commissure crosses midline

Question 9

White matter of spinal cord

Answer 9

surrounds gray matter
median fissure deeper than posterior median sulcus
anterior, lateral, and posterior white column (funiculi) contain axons that form ascending and descending tracts

Question 10

Connective tissue coverings

Answer 10

endoneurium (wrapping of each nerve fiber)
perineurium (surrounding group of nerve fibers forming fascicle)
epineurium (covering of entire nerve)

Question 11

Nerve v neuron

Answer 11

nerve is a cluster of neurons with blood vessel (needs blood for the individual cells)
neuron is a single cell

Question 12

Spinal nerves (motor fibers)

Answer 12

ventral root of each spinal nerve contains axons of somatic motor and visceral motor

Question 13

Spinal reflexes

Answer 13

automatic response to change in environment
integration center for spinal reflexes is gray matter (somas of neurons) of spinal cord
somatic (refers to body) will always be skeletal muscle contraction
autonomic (visceral reflexes) involve smooth and cardiac muscles and glands (involuntary reflexes)